Republican Senate nominee Gabriel E. Gomez’s runaway victory in Tuesday’s primary delivers an unwelcome jolt to Massachusetts Democrats, with the dynamics of the race offering an unnerving comparison to the 2010 Senate election that still haunts many of them.

Indeed, on paper, the 47-year-old Gomez can lay claim to many of the traits that helped propel Scott Brown into the US Senate: youthful-looking, camera-friendly, a military background, and barely a blip on the Democrats’ radar just months before winning the primary. Unlike Brown, he has no political experience, but has a stint in private equity and service as a Navy SEAL.

That’s stacked against the Democratic nominee, US Representative Edward J. Markey, who is 66 years old, and has served in Congress since 1977.